velocity gain from 6 inch gp100 to 12 inch contender

[bjarrell]

Could someone give me a rough estimate about how much velocity I can expect to gain going from a 6 inch gp100 to a 12 inch contender?  I use the 180 grain federal castcore load that is advertised at 1130fps.  Thank you.

[Hopalong7]

    The increase in barrel length of course will contribute some velocity gain, but the sealed breach(no cylinder gap) will be the biggest factor.  I don't recall running a similar load across my cronograph and don't have a GP100 anymore, so I'm just guessing...but I'd expect around 300fps more. 
Walt

[shot1]

I also would agree on 300 fps or so increase. I have chorno-ed a hand load with the 180 gr XTP in my 10" Contender and got 1400 fps and the loading books that use 6 to 8" revolvers list this load in the 1050 to 1100 fps range. This is by the way a very accurate load and it hammers deer out to 107 yards which is as far as I have shot one with it. It is the MAX load given by Hodgdon for H-110 and 180 gr Jacketed bullets.

About 30 years ago when I got my first 10" 357 mag Contender barrel I went out and shot some OLD SCHOOL hand loads with 2400 powder and 158 JHP ( they don't even come close to listing that much powder these days in the manuals)  that were stiff but OK in a number of revolvers. On the first shot from the Contender I had a hard time opening it up and I had to take a pocket knife to pry the case out of it. That tells you that your pressure is much higher in the no cylinder gap Contenders. 

[Ranger413]

I'm putting together a G2 Contender in handgun set-up.  Right now I've got .44 Mag, .223, and .22 l.r. barrels and the frame should be at the dealer's shop today.  I was doing some reading in the reloading manual and was blown away at the velocity difference between the chart for a 7 1/2" Blackhawk and a 14" contender.  Using 240gr. Hornady XTP bullets and max loads of H110 the difference was about 400 fps.  I think they said it was only about 150 fps less than a Ruger Carbine.  Wow!

I'm planning on doing some load work-up for the .44 and .223.  I'll be interested to see the performance difference on game with the .44 with the velocity gain.  I may even step up to 300gr. bullets.

[flipajig]

I have 3 44 mags a Super 14 tender,SBH, and a Wichester M94
In my tender im getting 1600fpf and 1800 with the Winchester and the mid 13's with the SBH
all 3 the same load a good dose of 2400 and a 200 grn Nosler JHP.